import java.util.Scanner;
public class Triangle
{
	public static class Delta
	{
		int x;
	     int y;
		 int z;
		public  Delta(int a,int b,int c)
		{
			x=a;
			y=b;
			z=c;
		}
		public double Acreage()
		{
			double S;
			S=Math.sqrt((x+y+z)*(x+y-z)*(x+z-y)*(y+z-x))*(0.25);
			return S;
		}
		public int Girth()
		{
			int C;
			C=x+y+z;
			return C;
		}
	}
	public static void main(String args[])
	{
		Delta a=new Delta(3,4,5);
		System.out.println("三角形的面积为："+a.Acreage());
		System.out.println("三角形的周长为："+a.Girth());
	}
}